Car-retarder system



March 3, 193,1. aWI K, HOWE l 1,-794-,619

CAR RTRDER SYSTEM Filed Feb. 14, 1927 Patented Mar. Y.'55, 1931A i bear against the UNITED `i STA WINTHROBK. Howe, or ROCHESTER, [New YoRx,"AssIGNoRjtro GENERAL RAILWAY v SIGNAL coMrANY, or ROCHESTERNEW YORK 1 V oAR'RETA/RDER SYSTEM.v

Appiieatitn flied Februari-511.14, i927. serial fixaiespos.,

This invent-ion relates infgeneralto' the braking of'railway vehicles, and has more particular referenceto brake ineansf'posi-l tioned alongvthe trackand having 'spring pressed brake shoes arranged to frictionally sidesof'the wheels of a passing vehicle.

In retarders,ofthisvcharacter, itis usual to provide acontrollevermovable to various positions to .cause the brake shoes to assume andl hold various positions resultingv indif- Y fering degrees -of retardation. ThisV operai tion vof the car retarder yas.. awhole, except -tion contemplates car wheels of constant Width", but in practiceit is yfound that cai'- wheels vary. as much as 3A inthicknesslthus yresulting in varyingv the retardingjeffect for a. given position Aof, the Ycont'rol'lever. With heavy cars, this atfmost merely changes the-y actual retardation from the contemplated,

and the operator canniove the control lever to compensate for the variationl of retarda tiondue to variation linwlieel thickness, but

with light cars, before it can be compensated for', excessretardation may,` cause .the car to ride up on the top of the retarder. .y Y v For a further and more detailed descripfor the novel spring driving connection, at-

kconnection for the main'fsprings, and ar-4 y istic features of the invention will appear as" tention is called to applicants co-pendingapv plie-ationy Serial No. 70,599' filed November Withthe above and other considerations in mind-it isy proposed, in accordance witlirthe present invention, to provide a car retarder of the above'type, with means for minimizing, to a practically negligible amount,'varia tions inv retardation of lightcars due to wheel thickness variations from normal. f More Vspecifically,incombination with the usual main retarder springs, there isvv used a single secondaryspring, arranged in the driving ranged to itselfcare for light retardatiom'and to be lcut out vof, operation athe'avy retardav tion which is produced by the mainsprings.

'Further objects, purposes, and character,-

solelybA l vention.j In thedrawings Fig. 1 isaplan view of a part of` a retarder,

constructedfinaccordance'lwith this inven'- 1 Fig. 2 is ja" sectional Vview on line 2--2 ofV I briely,andfor a more detailed and complete descriptiontliere'of, reference should be niade y way of example, `one 'form of the inl i curve illustrating the brake `pressure as a function of movementf e if e co' t Fig, t is a kplan view'of a detail,with parts to the above mentioned' pending application I Ser. No. 70,599. g

lthe "drawings'islshowiifa track foundby rails 1, and on each lside of each lrail are brake shoes 2, carrie-d'by anV arti cula.tedbrake bar 3. The brake bars 3 are connected, by rods t,v

pivotedtl'iereto at 5, tolugs (Sand 7 carried by brake actuatingy members l8 and 9 respective'- ly, such .actuating members being arranged` Y side by side inpairs'and operable, simultane Y ously, in opposite directions by ,ntie-ans"v of levers l1 connected ytheretol atf12`and- 13,

yand themselves port 15. y

Y: Thelevers 11 are operated by a pitman 1G,

pivoted at 14 to a fixed sup! tl'irough connecting' levers 17 and 18, tlie'pitn' manbeng moved to its various positions by a crank pin 19 operated by ainotoi or theflike v2O,,controlled by contact finger 21 and coneV v tactsj22, the iinger'beiiig operated by van arm shoes 2 relative to 'the lugs 6'- and `'l'. Secured on eachjifod 4 is an initially 'ten-sioned main reinitial'tension of the spring 26 can be adj ustedv at Will. i `f l l 'v "Eaclilof'therods ellis furnishedwitli lock 1 nuts and bearing plates 25, for permittiiig adjustment of th'einitial position of'theb'rake ,',6 and?, the members lE27-29 being slidablefon` y Y ytherodg- By operation yofthe screw 28,' the the' description progresses, reference being lhad to the accompanyingdrawings, showing, 190

lcient compression of the "spring ofl'tobiin einer v;

the spring` 3l equals th'ejsuin el the initial Included in the driving connection for the levers ll, is a coinpressible spring joint shown in detail in Fig. 4. This j oint includes a lione# ing 30, inclosing an initially tensioned spring 3l, bearingat one end against an end ofthe housing avndat. the other against piston', slidaole therein and carried by the pitiiiaii lr6, ar shoulder 32, on theV pitinan liinitingthe` in: ward niotion of: the piston Ain the housing.`

The curve shown in Fig. 3, represents the pressures exerted on the bra-ke shoes 2, cor

responding to movement of the c-iiilt ipin 19,5

when a car is in the retarder. The vertical part 33 ot' the curve represents-the initial tension of springv3l, the relatively flat portion 3i represents the tension iii spring* 3l as the pisteii `32 for-edfinto Itheilioiisin"gfyuntil stopped by the` slioiil'deii 32?, the relativesneep portioii represents the variation of tension exerted inthe active inaiii springs-Q6 f-iyaiio'us operating positions, the initial tension oit theniain springs being suchthattlie juni of the initial tensinfsaof those spriiigszth'at are active at anyone tini'e is equal to the press re L' at the point 36 ofthe cui-ve.

Thedevic'e', as described above, operates in the iolloivingvmanner. On ei'ie'rgi'z'ation of 4the iiiotorEZO, the crank pin 19 as'suines one of its operative positions, as indicated iii dotted lines in VFig. l, depending'` iip'oi'i'tl'iey position of contaet. 2l and thus .drives the pitin'aii lf3 to ni'ove the bia'lieshoes inivf 'd ly towards the track railsviylien the l"retarder isirot occupied by 'a car.A The initial tension fof sp'rinOBl is suiiicientto cause inoveine'iito the oitniaii 16 durin'o the tirstt'woojerative positions p Spf (see Fig. s). tocorrespon'dingl nieve 'the brake'sh'oe 2 'ivithoiitcaiisinig C) the slioi'ilder 32 against therhbiis'ii- 30,A Tn rds', the c'o'iiipie'sible s1 L: joint shown in functions like "onifpressible rod vfor the liiist two positions thereafter Viiinctio'n's as a. rigid rod.' On niov U ing' the crank pin 19 to positions pi and 73e', the

spring 3l is *eoinpressed byvino ement 'ofthe pi n 32 into the hon ng 3() 'l'iitil stopped by ie 'slimmer ,is

teiisiens ot the inain retarder springs 26 which are active when the retarder is occupied, so that thesprings 26 are coinpressedsto increase the tension "on the brake shoes 2. Tl'ius it Will be seen that forthe first t'vvo positions paiid 492, when die retarder-'is Occupied., the com* pressib-lejoliiit is compressed until stopped by the shoifil'der thielsplings '26 in the ni'eantii'ne tilinctioiiinfg as Ithough rigid, their initial tension is too high to peinit coinpression thereor", vvhile atpositionsffo3 and 79'? the "pitinan iiiinctioii's lil'ea rigid rod, 'and the S is cared for by the spring 3l, then this spring or the first partei the opei'atiioi'iiof the "crai'il pin ni the entire @einwenig-,of the brak@ she-es becomes ineffective to exert any tension due to the cutting into action of the springs 26 havingan initial tension equal to the point 36 on v the curve ot Figli, and troni thereon the pres ysure on the bralfze shoes is exerted by means of the maia springe 2G.

' pointed out in a` general manner' at the `beginning ot this specification, the pressure curve resulting troni a sprung',V arrangement g as deseribned above, has a relatively flat portion 34 and a relatively steep portion 35. This pe"'i"iif'iits Werking the brake shoes in the iiat portion of the curve for light cars, whereby afvariatioii iii the `ivheel Width will cause only a slight variation in brake shoe pressure, and

` not siijhciei'it to cause the'car to' ridefup on the top 'of vtl 'i' retarder, 'For hea-vier' cars, the

retarder is Worked in the steep portioiiB- 'ot lthe CiirVe, ivli'ere aV variation in WheelV Width V Wll 'Cause a greater variationin pressure, which lioivever,in the ease 'ot a heavy car, 'will "notcause the car to. rideup on the' retarder.

havea less pronoui'i'cedeiieetfo'r the lighter l cars Where'- less 9r `e'ssiire'y ise'ierted'than it* 'ivill have iior'heavyf oars ivhere 'a higihpresjsureqis eierted, and for this reason it,V is desirable :to have spring ineanshaving' antiptu'rned pressure;deformation characteri'sticy Furthermore, byhaving' a pressure curve 'as shivn fin'F-ig. 'Sit is possibleto 'attain a high braking pressure by ivorlring in they portioiiof the curve, Without necessig 'as @realta niovenentot the actuating 'parts 'as `ivoiild necessary 'if the ci'irve were a straight line with a slope the saine as that porti'fii'i134.r In this manner, high pressiires nients'of the actuating parts. In other words, applicants arrangement affords. VaA car reler in' Vwhich 'spring' n'iean's :is employed fing' "an iur-turned pressure#deformation cliaracteristi'c.V s

l Thefiifiitial tensions of the springs 3l and Q6 ran be variedso as to bear diterent rel-ations to each `other tothereby change the pressure ciir've `troni theV 'one shown in 'Fig'. 3 to any desiredone-and it is contemplated that various relations between the initial tensions, and

alsothe rigidi-ty ofi-:the springs 3l and 26, will be used in accordance with the particular attendant circumstances. f

, The above' specific description of one forni ot theii en ion is `given' solely by vay of4 'eani'pld and is not intended, in any iiiaiiner ioo v of the wheels of passing'cars, a brake shoe,

whatsoever', in a limiting sense. Obviously, the invention can assume-many diii'ereiity physical forms, and-is susceptible of numerous modiiications, `and all such forms and modifications are intended to be included in this application, as come withinthe scope of the appended claims.

Having described my invention, I now claim V l. In a car retarder for engaging the sides actuating means for the shoe, tensioning means inthe actuating means, including, separate initially tensioned spring means arranged to have their tensions varied upon operation ofthe actuating means, and means to positively limit the tensioning of one of the spring means, to a tension substantially equal v to the active initial tension ofthe other spring means..A Y y 2. Ina car retarder of the type engaging the sides of passingwheels, a brake shoe, an

actuator for the brake shoe, andinitially tensioned separatespring vmeans for theshoe, variable by the actuator to follow a pressure curve having a relatively flat and a 'relatively steep portion directly connected one to the l other. f

1 3. In a car retarder of the type enga-ging thesides of passing wheels, a brake-shoe,

an actuator for the brake shoe, and initiallyl tensioned separate spring means forrthe shoe, variable by thevactu'atorto follow a pressure curve having a relatively flat anda Y relatively steep portion directlyl connected p one to the other.

l. In a car retarder of the type engaging lthe sides of passing wheels, a brake shoe,an actuator for the brak-eshoe, and initially tensioned'separate'spring means for the shoe, variable by the actuator to follow a pressure curve having a relatively'iat and a relatively steep portion directly connected one to the other, one of the spring means corresponding to the flat and the other to the steep portions, respectively.

5. In a car retarder, a brake shoe, an "actuating beam, an initially' tensioned main Y spring connection betweentlie shoe and beam,

an actuator for lthe beam, and a compressible spring joint inserted in the actuator.

6. In a' car retarder, a brake shoe,-anac tuating beam, an initially tensioned main spring connection between the shoe and beam, an actuator for the beam, and an initially tensioned compressiblespring joint inserted in the actuator.

- 7. In a car retarder, a brake shoe, an actuating beam, an initially tensioned main spring connection between theshoe and beam, an actuator for the beam, an initially tensioned compressible spring joint inserted iny the actuator, and means for positivelyy limiting the extent of compression ofthe spring joint.

Ving ay spring device having an lip-turned pressure-deformation characteristic.

v8. In a car retarder, a brake shoe, an actuating beam, and initially tensioned main an actuator for the beam, initially tensioned coinpressible spring joint inserted in the actuator, and mea-ns for positively limitingthe spring connection between the shoe and beam, i

extent of the compression of the spring joint v toinot exceed theinitial tension in theinain means included within said actuating means f orcausing the active pressure exerted by said brake shoes against thel carwheels tol increase at a lower rate kper unit of movement of the actuating *meansV for the lower pressures thanit increases per unit of movement of the actuating means for the higher pressures. v I f 10. In a car retarder for engaging the sidesv Vof ywheels ot passing'fcars, the combination.;A

with a track rail, brake Yshoes on opposite r l sides of said rail, shoe beams arranged parallel to said brake shoes, compression springs betweensaid shoe beams and brake shoes, acj.

tuating means for simultaneously moving said beamstowards said rail, and spring j means included within said actuating means `tor causing the' active .pressurev exerted by' increase. as compared with the extent of movement of the actuating means, thus constitut- VIn .testimony whereof I affix my signature.

izo

. WINTHROP K. i-iowii.` f

is?) j j ico said brake shoes against the car wheels ftor 

